玉米芯基保水剂对紫花苜蓿光合日变化特性的影响

Effect of Corn Cob-based Water Retention Agent on Diurnal Photosynthetic Characteristics of Medicago Sativa L

为探究保水剂对沙质土壤吸水持水能力和紫花苜蓿光合生长日变化特性的影响,以本课题组研发的玉米芯基保水剂和2年生紫花苜蓿为试验材料,采用盆栽人工给水和自然耗水相结合的方法,设置A、B、C、D四个保水剂添加处理(分别在100 g土壤中加入0、0.2、0.4和0.8 g保水剂),选择紫花苜蓿对土壤水分最为敏感的分枝期和现蕾期开展试验。结果表明,与处理A相比,不同添加处理均可提高土壤持水能力;能够有效缓解紫花苜蓿光合“午休现象”。处理C在试验周期内,土壤相对含水率保持在45.27%~70.67%间。与处理A相比,处理C的紫花苜蓿生物量提高了71.81%。说明玉米芯基保水剂用量为土壤重量的0.4%时,对紫花苜蓿光合特性的改良效果最佳。

To explore the effects of water retention agents on the water absorption and holding capacity of sandy soil and the diurnal variation characteristics of photosynthetic growth of Medicago sativa L,the corn cob-based water retention agent developed by our research group and 2-year-old alfalfa were used as experimental materials.The combination of potted artificial water supply and natural water consumption was used,and four water retention agents treatments A,B,C,and D were designed(0,0.2,0.4,and 0.8 g of water retention agents were added to 100 g of soil,respectively).The experiment was conducted in the branch stage and bud stage of Medicago sativa L,which were the most sensitive to soil moisture.The results showed that compared with treatment A,different additive treatments could improve the soil water holding capacity,and it could effectively alleviate the photosynthetic"lunch break phenomenon"of Medicago sativa L.During the experimental period,the relative soil moisture content of treatment C remained between 45.27% and 70.67%.Compared with treatment A,Medicago sativa L biomass of treatment C increased by 71.81%.It indicates that when the amount of corn cob-based water retention agent is 0.4%of soil weight,Medicago sativa L has the best effect of improving photosynthetic characteristics.